Tools for sheathing treatment devices and associated systems and methods

ABSTRACT

Devices for loading intravascular treatment devices into a sheath and associated systems and methods are disclosed herein. A sheathing tool may include, for example, a first channel extending to a first opening, the first channel configured to receive a treatment device in a constrained state therethrough. The treatment device may include an elongated member and a first element and a second element at a distal region of the elongated member. The second channel may extend to a second opening, the second opening surrounded by a sidewall and configured to receive the treatment device in the constrained state therethrough, wherein the second opening is spaced apart from the first opening by a gap, and wherein a length of the gap is great enough to allow the first element to self-expand over the sidewall while the second element generally maintains its diameter in the constrained state while crossing the gap.

TECHNICAL FIELD

The present technology relates generally to sheathing tools and associated systems and methods. Some embodiments of the present technology relate to devices for loading an intravascular treatment device into a sheath.

BACKGROUND

Many medical procedures use medical device(s) to remove an obstruction (such as clot material) from a body lumen, vessel, or other organ. An inherent risk in such procedures is that mobilizing or otherwise disturbing the obstruction can potentially create further harm if the obstruction or a fragment thereof dislodges from the retrieval device. If all or a portion of the obstruction breaks free from the device and flows downstream, it is highly likely that the free material will become trapped in smaller and more tortuous anatomy. In many cases, the physician will no longer be able to use the same retrieval device to again remove the obstruction because the device may be too large and/or immobile to move the device to the site of the new obstruction.

Even in successful procedures, a physician must be cautious to prevent the walls of the vessel or body lumen from imparting undesired forces to shear or dislodge the obstruction as it passes through the vasculature during removal. These forces have the potential of fragmenting the obstruction. In some cases, the obstruction can simply break free from the retrieval device and can lodge in a new area causing more concern than the original blockage.

Procedures for treating ischemic stroke by restoring flow within the cerebral vasculature are subject to the above concerns. The brain relies on its arteries and veins to supply oxygenated blood from the heart and lungs and to remove carbon dioxide and cellular waste from brain tissue. Blockages that interfere with this blood supply eventually cause the brain tissue to stop functioning. If the disruption in blood occurs for a sufficient amount of time, the continued lack of nutrients and oxygen causes irreversible cell death (infarction). Accordingly, it is desirable to provide immediate medical treatment of an ischemic stroke. To access the cerebral vasculature, a physician typically advances a catheter from a remote part of the body (typically a leg) through the abdominal vasculature and into the cerebral region of the vasculature. Once within the cerebral vasculature, the physician deploys a device for retrieval of the obstruction causing the blockage. Concerns about dislodged obstructions or the migration of dislodged fragments increases the duration of the procedure at time when restoration of blood flow is paramount. Furthermore, a physician might be unaware of one or more fragments that dislodge from the initial obstruction and cause blockage of smaller more distal vessels.

Many physicians currently perform thrombectomies (i.e. clot removal) with stents to resolve ischemic stroke. Typically, the physician deploys a stent into the clot in an attempt to push the clot to the side of the vessel and re-establish blood flow. Tissue plasminogen activator (“tPA”) is often injected into the bloodstream through an intravenous line to break down a clot. However, it takes for the tPA to reach the clot because the tPA must travel through the vasculature and only begins to break up the clot once it reaches the clot material. tPA is also often administered to supplement the effectiveness of the stent. Yet, if attempts at clot dissolution are ineffective or incomplete, the physician can attempt to remove the stent while it is expanded against or enmeshed within the clot. In doing so, the physician must effectively drag the clot through the vasculature, in a proximal direction, into a guide catheter located within vessels in the patient's neck (typically the carotid artery). While this procedure has been shown to be effective in the clinic and easy for the physician to perform, there remain some distinct disadvantages using this approach.

For example, one disadvantage is that the stent may not sufficiently retain the clot as it pulls the clot to the catheter. In such a case, some or all of the clot might remain the vasculature. Another risk is that as the stent mobilizes the clot from the original blockage site, the clot might not adhere to the stent as the stent is withdrawn toward the catheter. This is a particular risk when passing through bifurcations and tortuous anatomy. Furthermore, blood flow can carry the clot (or fragments of the clot) into a branching vessel at a bifurcation. If the clot is successfully brought to the end of the guide catheter in the carotid artery, yet another risk is that the clot may be “stripped” or “sheared” from the stent as the stent enters the guide catheter. Regardless, simply dragging an expanded stent (either fully or partially expanded) can result in undesired trauma to the vessel. In most cases, since the stent is oversized compared to the vessel, dragging a fixed metallic (or other) structure can pull the arteries and/or strip the cellular lining from the vessel, causing further trauma such as a hemorrhagic stroke (leakage of blood from a cerebral vessel). Also, the stent can become lodged on plaque on the vessel walls resulting in further vascular damage.

In view of the above, there remains a need for improved devices and methods that can remove occlusions from body lumens and/or vessels.

SUMMARY

At least some of the embodiments disclosed herein are devices, systems, and methods for facilitating a user in positioning an expandable, intravascular treatment device within a lumen of a catheter and/or sheath. For example, certain medical procedures may require multiple passes of the same treatment device in order to effectively treat the patient. Between passes, the treatment device is often completely removed from the catheter and/or patient and must be re-loaded into the catheter for the next pass. For instance, removing clot material from a blood vessel of a patient may include advancing a clot retrieving device to a treatment site within the blood vessel lumen, capturing at least a portion of the clot material with the clot retrieving device, removing the clot material and clot retrieving device from the patient, then repeating the foregoing process until a sufficient amount of clot material is removed.

Some embodiments of the present technology include a device for sheathing (and/or re-sheathing) a treatment device, such as a clot retrieving device. In some embodiments, the device includes a first channel and a second channel, each of which are configured to receive the treatment device in a constrained state therethrough. In some embodiments, the first channel may extend to a first opening and the second channel may extend to a second opening that is surrounded by a sidewall. The second opening may be spaced apart from the first opening by a gap, and the length of the gap may be great enough to allow a first portion of the treatment device to self-expand over the sidewall while a second portion of the treatment device generally maintains its diameter in the constrained state while crossing the gap.

The subject technology is illustrated, for example, according to various aspects described below. Various examples of aspects of the subject technology are described as numbered clauses (1, 2, 3, etc.) for convenience. These are provided as examples and do not limit the subject technology. It is noted that any of the dependent clauses may be combined in any combination, and placed into a respective independent clause, e.g., clause (1, 16, 20, 23, etc.). The other clauses can be presented in a similar manner.

-   -   1. A device for sheathing a treatment device having an elongated         member and a first element and a second element at a distal         region of the elongated member, wherein the device comprises:         -   a first channel extending to a first opening, the first             channel configured to receive the treatment device in a             constrained state therethrough; and         -   a second channel extending to a second opening, the second             opening surrounded by a sidewall and configured to receive             the treatment device in the constrained state therethrough,             wherein the second opening is spaced apart from the first             opening by a gap, and wherein a length of the gap is great             enough to allow the first element to self-expand over the             sidewall while the second element generally maintains its             diameter in the constrained state while crossing the gap.     -   2. The device of Clause 1, wherein an inner diameter of the         second channel tapers distally from the second opening.     -   3. The device of Clause 1 or Clause 2, wherein an outer diameter         of the sidewall increases distally from the second opening.     -   4. The device of any one of Clauses 1-3, wherein the first and         second openings are fixed relative to one another such that the         length of the gap is fixed.     -   5. The device of any one of Clauses 1-4, wherein the first and         second openings are movable relative to one another such that         the length of the gap is adjustable.     -   6. The device of any one of Clauses 1-5, wherein the first         channel is within a first housing and the second channel is         within a second housing movable relative to the first housing,         and wherein the first housing has a detent configured to receive         a protrusion of the second housing, or vice versa, such that the         first housing is locked in place relative to the second housing.     -   7. The device of any one of Clauses 1-6, wherein the first         channel is configured to receive a sheath therethrough, wherein         the sheath is configured to slidably receive the treatment         device therein in the constrained state.     -   8. The device of any one of Clauses 1-7, wherein the second         channel is configured to receive a sheath therethrough, and         wherein the sheath is configured to slidably receive the         treatment device therein in the constrained state.     -   9. The device of any one of Clauses 1-8, wherein the first         element is a self-expanding element.     -   10. The device of any one of Clauses 1-9, wherein the second         element is a self-expanding element.     -   11. The device of any one of Clauses 1-10, wherein the first         element is a mesh.     -   12. The device of any one of Clauses 1-11, wherein the second         element is a stent.     -   13. The device of any one of Clauses 1-12, wherein, in an         expanded state, the first element has a flared distal region         with a lumen therethrough, and wherein the lumen of the flared         distal region is configured to receive the sidewall therein as         the treatment device is moved through the across the gap.     -   14. The device of any one of Clauses 1-13, wherein the treatment         device is a clot retrieving device.     -   15. The device of any one of Clauses 1-14, wherein the device is         configured to be detachably coupled to a handle of a catheter,         thereby placing the second channel in fluid communication with a         lumen of the catheter.     -   16. A system for sheathing a treatment device having an         elongated member and a first element and a second element at a         distal region of the elongated member, wherein the device         comprises:         -   a sheath configured to receive the treatment device in a             constrained state therethrough;         -   a first channel extending to a first opening and configured             to receive at least a portion of the sheath; and         -   a second channel extending to a second opening, the second             opening surrounded by a sidewall and configured to receive             the treatment device in the constrained state therethrough,             wherein the second opening is spaced apart from the first             opening by a gap, and wherein a length of the gap is great             enough to allow the first element to self-expand over the             sidewall while the second element generally maintains its             diameter in the constrained state while crossing the gap.     -   17. The system of Clause 16, further comprising a fluid port         coupled to a proximal end portion of the sheath.     -   18. The system of Clause 16 or Clause 17, wherein the sheath is         a first sheath and the system further comprises a second sheath         configured to receive the treatment device in a constrained         state therethrough, and wherein the second channel is configured         to receive at least a portion of the second sheath therein.     -   19. The system of Clause 18, further comprising a catheter, and         wherein the second sheath is configured to be coupled to the         catheter.     -   20. A system for sheathing a treatment device having an         elongated member and a first element and a second element at a         distal region of the elongated member, wherein the device         comprises:         -   a sheath configured to receive the treatment device in a             constrained state therethrough;         -   a sheathing tool comprising:             -   a first channel extending to a first opening and                 configured to receive at least a portion of the sheath,                 and             -   a second channel extending to a second opening, the                 second opening surrounded by a sidewall and configured                 to receive the treatment device in the constrained state                 therethrough, wherein the second opening is spaced apart                 from the first opening by a gap, and wherein a length of                 the gap is great enough to allow the first element to                 self-expand over the sidewall while the second element                 generally maintains its diameter in the constrained                 state while crossing the gap;         -   a housing configured to be detachably coupled to the sheath             and the sheathing tool, wherein a majority of the length of             the sheath is contained within a perimeter of the housing             such that a user may position manipulate both ends of the             sheath and/or treatment device without taking a step.     -   21. The system of Clause 20, wherein the sheath is a first         sheath and the system further comprises a second sheath         configured to receive the treatment device in a constrained         state therethrough, and wherein the second channel is configured         to receive at least a portion of the second sheath therein.     -   22. The system of Clause 21, further comprising a catheter, and         wherein the second sheath is configured to be coupled to the         catheter.     -   23. A method for sheathing a treatment device having an         elongated member and a first element and a second element at a         distal region of the elongated member, the method comprising:         -   positioning the treatment device in a first channel with the             first and second elements in a constrained state;         -   moving the treatment device from a first opening of the             first channel through a second opening of a second channel             spaced apart from the first opening by a gap; and         -   while moving the treatment device across the gap, generally             maintaining a cross-sectional dimension of the first element             at its cross-sectional dimension in the constrained state             while allowing the second element to expand over a sidewall             surrounding the second opening.     -   24. The method of Clause 23, further comprising moving a portion         of the second element in a first direction through the second         channel while moving a second portion of the second element in a         second direction opposite the first direction outside of the         channel.     -   25. The method of Clause 23 or Clause 24, further comprising         moving the treatment device along the first channel in a first         direction, and wherein moving the treatment device from the         first opening and through the second opening is in a second         direction opposite the first direction.     -   26. The method of any one of Clauses 23-25, wherein moving the         treatment device from the first opening and through the second         opening in the second direction occurs after moving the         treatment device along the first channel in the first direction.     -   27. The method of any one of Clauses 23-26, further comprising         moving the treatment device along the second channel in a first         direction, and wherein moving the treatment device from the         first opening and through the second opening is in a second         direction opposite the first direction.     -   28. The method of Clause 27, wherein moving the treatment device         from the first opening and through the second opening in the         second direction occurs after moving the treatment device along         the second channel in the first direction.     -   29. The method of any one of Clauses 23-28, wherein the         constrained state is a first constrained state and the treatment         device is movable to a second constrained state in which the         second element is inverted relative to its position when the         treatment device is in a first constrained state.     -   30. The method of Clause 29, further comprising inverting the         second element by moving the first element through the second         channel while the second element surrounds the sidewall.     -   31. The method of Clause 29 or Clause 30, further comprising         moving the treatment device in the second constrained state         through the second channel.     -   32. The method of any one of Clauses 29-31, further comprising         moving the treatment device in the second constrained state         through the second channel and into a catheter.     -   33. The method of any one of Clauses 23-32, further comprising         decreasing a length of the gap before moving the treatment         device through the first opening.     -   34. The method of any one of Clauses 23-33, further comprising         decreasing a length of the gap after moving the treatment device         across a portion of the gap.     -   35. The method of any one of Clauses 23-34, further comprising         removing the treatment device from a catheter before positioning         the first and second elements in the first channel.     -   36. The method of Clause 35, further comprising removing clot         material from the treatment device before positioning the first         and second elements in the first channel.     -   37 The method of Clause 36, wherein removing clot material         includes rinsing clot material from the treatment device.     -   38. The method of Clause 35, further comprising removing clot         material from the treatment device while at least a portion of         the elongated member is positioned within the first channel but         before positioning the first and second elements in the first         channel.     -   39. The method of Clause 38, wherein removing clot material         includes rinsing clot material from the treatment device.     -   40. A device for transferring an intravascular treatment device         from a first sheath to a second sheath, the treatment device         including first and second self-expanding elements, wherein each         of the first and second sheaths is sized such that the treatment         device is constrained in a compressed state when positioned         within each of the first and second sheaths, and wherein the         device comprises:         -   a first channel configured to receive at least a portion of             the first sheath therein, the first channel having a first             proximal opening configured to receive the first sheath             therethrough and a first distal opening; and         -   a second channel configured to receive at least a portion of             the second sheath therein, the second channel having a             second proximal opening and a second distal opening             configured to receive the second sheath therethrough,         -   wherein the device is configured to securely position the             first and second channels relative to one another such that             the first distal opening is aligned with the second proximal             opening and spaced apart from the second proximal opening by             a gap, the gap having a length such that, when the first and             second sheaths are positioned within the first and second             channels, respectively, and the treatment device is moved             from the first sheath to the second sheath across the gap, a             distal region of the first element expands from the             compressed state within the gap while the second element             generally maintains its diameter in the compressed state             while crossing the gap.     -   41. The device of Clause 40, wherein the second channel is         surrounded by a sidewall having an outer diameter, and wherein         the distal region of the first element expands over the outer         diameter of the sidewall as it crosses the gap.     -   42. The device of Clause 40 or Clause 41, wherein an inner         diameter of the second channel tapers distally from the second         proximal opening.     -   43. The device of any one of Clauses 40-42, wherein the second         channel is surrounded by a sidewall having an outer diameter         that increases distally from the second proximal opening.     -   44. The device of any one of Clauses 40-43, wherein the first         and second channels are fixed relative to one another.     -   45. The device of any one of Clauses 40-44, wherein the first         and second channels are movable relative to one another.     -   46. The device of any one of Clauses 40-45, wherein the length         is a first length, and wherein the device is configured to         securely position the first and second channels relative to one         another such that the gap has a second length greater than the         first length.     -   47. A sheathing tool, comprising:         -   a support;         -   a loading member coupled to the support and having a first             distal opening, a first proximal opening, and a first             channel extending therebetween, wherein the first proximal             opening is configured to receive a first sheath             therethrough; and         -   a receiving member coupled to the support and having a             second distal opening, a second proximal opening, and a             second channel extending therebetween, wherein the second             distal opening is configured to receive a second sheath             therethrough,         -   wherein the support is configured to securely position the             loading member and the receiving member relative to one             another such that the first distal opening is aligned with             the second proximal opening and spaced apart from the second             proximal opening by a gap, the gap having a length such             that, when the first and second sheaths are positioned             within the first and second channels, respectively, and a             self-expanding treatment device is moved in a compressed             state from a lumen of the first sheath to a lumen of the             second sheath across the gap, a distal portion of the             treatment device maintains its diameter in the compressed             state between the first distal opening and the second             proximal opening.

Additional features and advantages of the subject technology are described below, and in part will be apparent from the description, or may be learned by practice of the subject technology. The advantages of the subject technology will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Many aspects of the present technology can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale Instead, emphasis is placed on illustrating clearly the principles of the present disclosure.

FIG. 1 is a schematic overview of a treatment system configured in accordance with the present technology.

FIG. 2 is a side view of a distal portion of the treatment device shown in FIG. 1 in a second position in accordance with embodiments of the present technology.

FIG. 3A is an isometric view of a sheathing tool in a first position configured in accordance with the present technology.

FIG. 3B is an isometric view of the sheathing tool of FIG. 3A in a second position configured in accordance with the present technology.

FIG. 3C is a top view of the sheathing tool in the first position, as shown in FIG. 3A.

FIG. 3D is a top view of the sheathing tool in the second position, as shown in FIG. 3B.

FIG. 3E is an enlarged, isolated, cross-sectional view of the first channel shown in FIGS. 3A-3D.

FIG. 3F is an enlarged, isolated view, cross-sectional view of the second channel shown in FIGS. 3A-3D.

FIGS. 4A-4H illustrate a method of using a sheathing tool to sheath a treatment device.

FIGS. 5A and 5B are an isometric view and a top cross-sectional view, respectively, of a sheathing tool shown in a first position configured in accordance with some embodiments of the present technology.

FIGS. 5C and 5D are an isometric view and a top cross-sectional view, respectively, of the sheathing tool shown in FIGS. 5A and 5B in a second position configured in accordance with some embodiments of the present technology.

FIGS. 6A and 6B are a top view and a side cross-sectional view, respectively, of a sheathing tool shown in a first position configured in accordance with some embodiments of the present technology.

FIG. 7A is an isometric view of a sheathing tool in a first position configured in accordance with the present technology.

FIG. 7B is an isometric view of the sheathing tool of FIG. 7A in a second position configured in accordance with the present technology.

FIG. 7C is a side cross-sectional view of the sheathing tool as shown in FIG. 7B.

FIG. 7D is an isometric view of the connector of the sheathing tool shown in FIGS. 7A-7C.

FIG. 8A is an isometric view of a sheathing tool in a first position configured in accordance with the present technology.

FIG. 8B is a side cross-sectional view of the sheathing tool of FIG. 8A in a second position configured in accordance with the present technology.

FIG. 8C is an isometric view of the connector of the sheathing tool shown in FIGS. 8A and 8B.

FIG. 9A is an isometric view of a sheathing tool in a first position configured in accordance with the present technology.

FIG. 9B is an isometric view of the sheathing tool of FIG. 7A in a second position configured in accordance with the present technology.

DETAILED DESCRIPTION

The present technology provides devices, systems, and methods for sheathing and/or re-sheathing an intravascularly deliverable treatment device. Although many of the embodiments are described below with respect to devices, systems, and methods for removing clot material/treating embolism (such as a cerebral embolism), the sheathing tools of the present technology may be used to re-sheath any intravascularly deliverable, expandable treatment device. Other applications and other embodiments in addition to those described herein are within the scope of the technology. For example, the sheathing tools of the present technology may be used with devices for removing emboli from body lumens other than blood vessels (e.g., the digestive tract, etc.) and/or may be used to remove emboli from blood vessels outside of the brain (e.g., pulmonary blood vessels, blood vessels within the legs, etc.). In addition, the sheathing tools of the present technology may be used with devices for removing luminal obstructions other than clot material (e.g., plaque, resected tissue, etc.).

1. System Overview

FIG. 1 is a schematic representation of a system 1 (“system 1”) configured in accordance with the present technology. As shown in FIG. 1, the system 1 may include a treatment device 10 (shown in an expanded, unconstrained state), a catheter 100 (e.g., a microcatheter), a sheathing tool 200 (shown schematically), a support 300, and a sheath 19 for facilitating introduction of the treatment device 10 to the catheter 100 and/or sheathing tool 200. The catheter 100 may include a handle 102 and an elongated shaft 104 having a proximal portion 104 a coupled to the handle 102 and a distal portion 104 b configured to be positioned at a treatment site within a blood vessel lumen (e.g., a cerebral blood vessel lumen). The elongated shaft 104 is configured to slidably receive the treatment device 10 in a low-profile, constrained state (not shown) therethrough.

The sheath 19 may be configured to be detachably coupled to the catheter 100, the sheathing tool 200, and/or the support 300 and is configured to slidably receive the treatment device 10 in a low-profile, constrained state (not shown) therethrough. In some embodiments, such as the embodiment shown in FIG. 1, the sheath 19 may include a first segment 31 and a second segment 33. The first segment 31 may have a proximal portion 31 a and a distal portion 31 b configured to be detachably coupled to the sheathing tool 200, and the second segment 33 may have a proximal portion 33 a configured to be detachably coupled to the sheathing tool 200 and a distal portion 33 b configured to be detachably coupled to the handle 108 of the catheter 100, thereby creating a pathway between the lumen of the second segment and the lumen of the elongated shaft 104.

As shown in FIG. 1, the sheathing tool 200 and/or one or more portions of the sheath 19 may be configured to be detachably or permanently coupled to the support 300. For example, to secure the sheathing tool 200 and/or the sheath 19 to the support 300, the support 300 may include one or more tabs, slots, protrusions or other means 302 for engaging the sheath 19 and/or the sheathing tool 200 and/or one or more corresponding tabs, protrusions, slots, etc. on the sheath 19 and/or the sheathing tool 200. In some embodiments, the system 1 may be packaged with one or both of the sheathing tool 200 and the sheath 31 detachably or permanently mounted on the support 300.

In some embodiments, the treatment device 10 includes an elongated member 12 and a treatment assembly 14 coupled to a distal region of the elongated member 12. The treatment assembly 14 may be configured to be intravascularly positioned at or adjacent clot material within a blood vessel lumen and includes a first element 17 and a second element 15. In some embodiments, the first element 17 may be a self-expanding stent 17 (e.g., a laser-cut stent) and the second element 15 may be a self-expanding mesh (e.g., a braid, a weave, a lattice structure, a fabric, etc.). In some embodiments, the first and second elements 17, 15 may have other suitable configurations.

The first element 17 may have a proximal portion 17 a coupled to the elongated member 12 and a distal portion 17 b, and the second element 15 may have a free end portion 15 b and a fixed end portion 15 a coupled to the elongated member 12. The second element 15 may be flexible such that it is movable between a first position (FIG. 1) in which its free end portion 15 b is proximal of its fixed end portion 15 a, and a second position (see FIG. 2) in which the second element 15 is inverted over the first element 17 such that a distal terminus of the second element 15 is at or distal to the distal terminus of the first element 17. As shown in FIG. 2, when the second element 15 is in the second position, the free end portion 15 b is distal of the fixed end portion 15 a and distal of the distal terminus of the first element 17. In the second position, the second element 15 may have a flared distal region 25 that surround a lumen 27 therethrough.

Examples of suitable treatment devices 10 for use with the system 1 can be found in U.S. patent application Ser. No. 15/594,410, filed May 12, 2017, which is incorporated by reference herein in its entirety. Although the sheathing tools discussed below are described with reference to the treatment device 10 shown in FIGS. 1 and 2, the sheathing tools disclosed herein may be utilized to sheath or re-sheath any expandable treatment device deliverable through a catheter.

2. Selected Embodiments of Sheathing Tools and Associated Methods of Use

FIGS. 3A and 3C are an isometric view and a top view of a sheathing tool 200, respectively, in a first position configured in accordance with embodiments of the present technology. FIGS. 3B and 3D are an isometric view and a top view of the sheathing tool 200, respectively, in a second position configured in accordance with embodiments of the present technology. Referring to FIGS. 3A-3D together, the sheathing tool 200 may include a housing 202 having a first portion 212 and a second portion 222 slidably coupled to the first portion 212. The first portion 212 may include a first protrusion 210 and first arms 211 extending distally beyond the first protrusion 210, and the second portion 222 may include a second protrusion 220 and second arms 221 extending proximally beyond the second protrusion 220. The first and second arms 211, 221 can be coupled along at least a portion of their lengths and together surround an open interior region 208 of the housing 202 into which the first and second protrusions 210, 220 extend. As such, the first and second protrusions 210, 220 are spaced apart from the adjacent first and second arms 211, 221. In some embodiments, the first protrusion 210 is not spaced apart from the adjacent first arms 211.

FIG. 3E is an enlarged, isolated, cross-sectional view of a distal region of the first protrusion 210. As shown in FIG. 3E, the first protrusion 210 may include a first channel 216 extending distally from a proximal region of the proximal portion 212 of the housing 202 to a first opening 214. In some embodiments the first channel 216 may be configured to receive the treatment device 10 in a constrained state therethrough, and in some embodiments the first channel 216 may be configured to receive the sheath 19. In FIG. 3E, for example, the first sheath segment 31 is shown positioned within the first channel 216. The first channel 216 may be surrounded by a generally tubular sidewall having an outer diameter OD1 that tapers in a distal direction. An inner diameter ID1 of the first channel 216 may taper distally to help guide the first element 17 in a generally constrained state towards the second opening 224.

FIG. 3F is an enlarged, isolated, cross-sectional view of a proximal region of the second protrusion 220. As shown in FIG. 3E, the second protrusion 220 may include a second channel 226 extending proximally from a distal region of the distal portion 222 of the housing 202 to a second opening 224. In some embodiments the second channel 226 may be configured to receive the treatment device 10 in a constrained state therethrough, and in some embodiments the second channel 226 may be configured to receive the sheath 19. In FIG. 3F, for example, the second sheath segment 33 is shown positioned within the second channel 226. The second channel 226 may be surrounded by a generally tubular sidewall having an outer diameter OD2 that tapers in a proximal direction to facilitate positioning the second element 15 over the second protrusion 220. In some embodiments, an inner diameter ID2 of the second channel 216 may taper distally to help guide and/or deflect the first element 17 into the second channel 226 and/or the second sheath segment 33.

When the sheathing tool 200 is in a first position, the first and second openings 214, 224 are spaced apart by a gap g having a first length, and when the sheathing tool 200 is in a second position, the first and second openings 214, 224 are spaced apart by a gap g having a second length less than the first length. The second length may be great enough to allow the second element 15 to self-expand such that the second element 15 is positioned over the sidewall while the first element 17 generally maintains its diameter in the constrained state while crossing the gap g. In other words, because the first element 17 does not have enough space between the first and second openings 214, 224 to expand, the first element 17 crosses the gap g in a constrained state which allows the first element 17 to enter through the second opening 224. If the gap g is too long, the distal ends of the first element 17 may begin to expand/splay outwardly and prevent the first element 17 from entering the second channel 226. Likewise, if the gap g is too short, the second element 15 may not have enough room for the distal portion 15 b to flare radially outwardly to an extent that allows the second element 15 to extend over the second protrusion 222 and/or receive the second protrusion 222 within the lumen 27 (FIG. 2) of the distal region 15 b.

FIGS. 4A-4H illustrate a method of using the sheathing tool 200 to sheath and/or re-sheath the treatment device 10. As shown in FIG. 4A, in some embodiments the treatment device 10 may first be withdrawn proximally from a treatment site through the blood vessel V lumen and catheter 100. Once removed from the catheter 100, the treatment device 10 may be in an expanded, unconstrained state in the second position such that the second element 15 is inverted over the first element 17. As shown in FIG. 4B, the treatment device 10 in the second position may then be pulled proximally through the second sheath segment 33, then the sheathing tool 200, and into the first sheath segment 31. For example, a proximal end of the elongated member 12 may be inserted into an opening at the distal portion 33 b of the second segment 33, and the rest of the elongated member 12 may be pushed proximally through the second sheath segment 33, the sheathing tool 200, and at least a portion of the first sheath segment 31 (and/or pulled once the proximal end of the elongated member 12 exits a proximal portion 31 a of the first sheath segment 31). Once a distal portion of the treatment device 10 is aligned with or proximal of the first opening 214, the elongated member 12 may then be pushed distally, thereby advancing the first and second elements 17, 15 across the gap g, as shown in FIG. 4C. While moving the treatment device 10 across the gap, the first element 17 may maintain its cross-sectional dimension in the constrained state while the second element 15 expands over the sidewall surrounding the second opening 224. (In FIG. 4C, the first and second elements 17, 15 are shown in cross-section for ease of viewing the treatment device 10 within the gap g.) In some embodiments, the first element 17 may be advanced across the gap g and into the second opening 224 while the sheathing tool 200 is in the first position. In some embodiments, the first element 17 may only be advanced across a portion of the gap g (and not into the second opening 224) while the sheathing tool 200 remains in the first position.

As shown in FIG. 4D, the first portion 212 of the housing 202 may be moved towards the second portion 222 of the housing 202 and secured in place by one or more detents and/or other securement features of the housing 202. Moving the first and second openings towards one another forces the second protrusion 220 further within the lumen of the second element 15. As shown in FIGS. 4E and 4F, the elongated member 12 can be pushed proximally while the sheathing tool 200 is in the second position, thereby advancing the first element 17 further within the second channel 126 and/or second sheath segment 33. As the elongated member 12 is advanced distally, the second element 15 extends further distally along the second protrusion 220 until it's fixed end portion pulls the second element 15 into the second channel 226. As such, a portion of the second element may move in a first direction through the second channel while a second portion of the second element moves in a second direction opposite the first direction outside of the second channel 226. As shown in FIG. 4G, the second sheath segment 33 may then be coupled to the catheter 100. As shown in FIG. 4H, the elongated member 12 may be pushed proximally to transfer the treatment device 10 in the first position from the second sheath segment 33 to the catheter 100.

FIGS. 5A and 5B are an isometric view and a top cross-sectional view, respectively, of a sheathing tool shown in a first position configured in accordance with some embodiments of the present technology. FIGS. 5C and 5D are an isometric view and a top cross-sectional view, respectively, of the sheathing tool shown in FIGS. 5A and 5B in a second position configured in accordance with some embodiments of the present technology.

FIGS. 6A and 6B are a top view and a side cross-sectional view, respectively, of a sheathing tool 600 shown in a first position configured in accordance with some embodiments of the present technology. In some embodiments, such as that shown in FIGS. 6A and 6B, the housing 202 may be a single component and/or the first and second openings are spaced apart by a fixed distance.

FIG. 7A is an isometric view of a sheathing tool in a first position configured in accordance with the present technology. FIG. 7B is an isometric view of the sheathing tool of FIG. 7A in a second position configured in accordance with the present technology FIG. 7C is a side cross-sectional view of the sheathing tool as shown in FIG. 7B. FIG. 7D is an isometric view of the connector of the sheathing tool shown in FIGS. 7A-7C.

FIG. 8A is an isometric view of a sheathing tool in a first position configured in accordance with the present technology. FIG. 8B is a side cross-sectional view of the sheathing tool of FIG. 8A in a second position configured in accordance with the present technology. FIG. 8C is an isometric view of the connector of the sheathing tool shown in FIGS. 8A and 8B.

FIG. 9A is an isometric view of a sheathing tool in a first position configured in accordance with the present technology. FIG. 9B is an isometric view of the sheathing tool of FIG. 7A in a second position configured in accordance with the present technology.

3. Conclusion

This disclosure is not intended to be exhaustive or to limit the present technology to the precise forms disclosed herein. Although specific embodiments are disclosed herein for illustrative purposes, various equivalent modifications are possible without deviating from the present technology, as those of ordinary skill in the relevant art will recognize. In some cases, well-known structures and functions have not been shown and/or described in detail to avoid unnecessarily obscuring the description of the embodiments of the present technology. Although steps of methods may be presented herein in a particular order, in alternative embodiments the steps may have another suitable order. Similarly, certain aspects of the present technology disclosed in the context of particular embodiments can be combined or eliminated in other embodiments. Furthermore, while advantages associated with certain embodiments may have been disclosed in the context of those embodiments, other embodiments can also exhibit such advantages, and not all embodiments need necessarily exhibit such advantages or other advantages disclosed herein to fall within the scope of the present technology. Accordingly, this disclosure and associated technology can encompass other embodiments not expressly shown and/or described herein.

Throughout this disclosure, the singular terms “a,” “an,” and “the” include plural referents unless the context clearly indicates otherwise. Similarly, unless the word “or” is expressly limited to mean only a single item exclusive from the other items in reference to a list of two or more items, then the use of “or” in such a list is to be interpreted as including (a) any single item in the list, (b) all of the items in the list, or (c) any combination of the items in the list. Additionally, the terms “comprising” and the like are used throughout this disclosure to mean including at least the recited feature(s) such that any greater number of the same feature(s) and/or one or more additional types of features are not precluded. Directional terms, such as “upper,” “lower,” “front,” “back,” “vertical,” and “horizontal,” may be used herein to express and clarify the relationship between various elements. It should be understood that such terms do not denote absolute orientation. Reference herein to “one embodiment,” “an embodiment,” or similar formulations means that a particular feature, structure, operation, or characteristic described in connection with the embodiment can be included in at least one embodiment of the present technology. Thus, the appearances of such phrases or formulations herein are not necessarily all referring to the same embodiment. Furthermore, various particular features, structures, operations, or characteristics may be combined in any suitable manner in one or more embodiments. 

We claim:
 1. A system comprising: a treatment device having an elongated member, and a first element and a second element at a distal region of the elongate member; and a device for sheathing the treatment device, the device comprising: a first channel extending to a first opening, the first channel configured to receive the treatment device in a constrained state therethrough; and a second channel extending to a second opening, the second opening surrounded by a sidewall and configured to receive the treatment device in the constrained state therethrough, wherein the second opening is spaced apart from the first opening by a gap, and wherein a length of the gap is great enough to allow the first element to self-expand over the sidewall while the second element generally maintains its diameter in the constrained state while crossing the gap.
 2. The system of claim 1, wherein an inner diameter of the second channel tapers distally from the second opening.
 3. The system of claim 1, wherein an outer diameter of the sidewall increases distally from the second opening.
 4. The system of claim 1, wherein the first and second openings are fixed relative to one another such that the length of the gap is fixed.
 5. The system of claim 1, wherein the first and second openings are movable relative to one another such that the length of the gap is adjustable.
 6. The system of claim 1, wherein the first channel is within a first housing and the second channel is within a second housing movable relative to the first housing, and wherein the first housing has a detent configured to receive a protrusion of the second housing, or vice versa, such that the first housing is locked in place relative to the second housing.
 7. The system of claim 1, wherein the first channel is configured to receive a sheath therethrough, wherein the sheath is configured to slidably receive the treatment device therein in the constrained state.
 8. The system of claim 1, wherein the second channel is configured to receive a sheath therethrough, and wherein the sheath is configured to slidably receive the treatment device therein in the constrained state.
 9. The system of claim 1, wherein the first element is a self-expanding element.
 10. The system of claim 1, wherein the second element is a self-expanding element.
 11. The system of claim 1, wherein the first element is a mesh.
 12. The system of claim 1, wherein the second element is a stent.
 13. The system of claim 1, wherein, in an expanded state, the first element has a flared distal region with a lumen therethrough, and wherein the lumen of the flared distal region is configured to receive the sidewall therein as the treatment device is moved across the gap.
 14. The system of claim 1, wherein the treatment device is a clot retrieving device.
 15. The system of claim 1, wherein the device is configured to be detachably coupled to a handle of a catheter, thereby placing the second channel in fluid communication with a lumen of the catheter. 